QMN, which just started trading this month, is the only copycat ETF that employs a truly market-neutral strategy, Patti said, which will provide “consistent returns in all market conditions with low volatility.”

Critics of ETF copycats say hedge funds’ quarterly filings are outdated by the time they're read, according to Institutional Investor. Copycats cannot determine for sure why the hedge fund took a particular position, if it still holds it or what other investment it now holds.

Mazin Jadallah, founder and CEO of AlphaClone, counters that hedge fund positions are longer than generally believed and that their long-position gains produce much of their gains.

Hedge funds are sometimes criticized for being illiquid and charge high fees for uncertain returns, Reuters noted. As a group, hedge funds returned about 5 percent on average through September, while the Standard & Poor’s 500 gained 16.43 percent. Hedge funds charge a performance fee, which can be 20 percent or more, in addition to a management fee.

The TrimTabs Float Shrink ETF (TTFS), an actively managed ETF from AdvisorShares, gained 35 percent since launching last October, according to Reuters.